Known elevator systems typically confine all elevator components to the hoistway or the machine room. The hoistway is an elongated, vertical shaft having a rectangular base in which the elevator car translates. The hoistway houses, among other things, the car guide rails which are usually a pair of generally parallel rails, fixed to opposite walls near the center of each wall, and running the approximate length of the hoistway. A counterweight having a pair of guide rails is positioned adjacent to a third wall. The hoistway houses additional components including terminal landing switches, ropes and sheave arrangements, and buffers for the counterweight and the car.
It is essential that the elevator components are located and oriented with precision prior to and during operation. The interior walls of the hoistway must be properly dimensioned and aligned, and the physical interface between the hoistway walls and the elevator components must be capable of withstanding varying load during use. It is particularly essential that the guide rails on which the car rides are properly positioned and solidly maintained. For quality of ride and safety, the guide rails need to be precisely plumb, square and spaced to avoid car sway, vibration and knocking. Guide rails are typically steel, T-shaped sections in sixteen foot lengths. The position of guide rails within the hoistway affects the position of the hoisting machine, governor and overhead (machine room) equipment. The machine room is typically located directly above the hoistway. The machine room houses the hoist machine and governor, the car controller, a positioning device, a motor generator set, and a service disconnect switch.
An elevator system designed to conserve space and simplify installation is disclosed in U.S. Pat. No. 5,429,211, in which counterweight guiderails and one elevator guiderail are positioned generally against one hoistway wall. The second elevator guiderail, however, requires mounting on the opposite hoistway wall.
Because the various components of the hoistway and machine room require precise positioning and they produce varying and substantial loads, it is costly and complicated to assemble a typical traction elevator system.